id package:ghc-lib-parser

Identity function.

id x = x

This function might seem useless at first glance, but it can be very useful in a higher order context.

Examples

>>> length $ filter id [True, True, False, True]
3

>>> Just (Just 3) >>= id
Just 3

>>> foldr id 0 [(^3), (*5), (+2)]
1000

GHC uses several kinds of name internally:

• OccName: see GHC.Types.Name.Occurrence#name_types
• RdrName: see GHC.Types.Name.Reader#name_types
• Name: see GHC.Types.Name#name_types
• Id represents names that not only have a Name but also a Type and some additional details (a IdInfo and one of LocalIdDetails or GlobalIdDetails) that are added, modified and inspected by various compiler passes. These Var names may either be global or local, see GHC.Types.Var#globalvslocal
• Var: see GHC.Types.Var#name_types

Identifier

True when when the instance heads are the same e.g. both are Eq [(a,b)] Used for overriding in GHCi Obviously should be insensitive to alpha-renaming

Is this a dependency signature include? If so, we don't compile this include when we instantiate this unit (as there should not be any modules brought into scope.)

GHC generates an ImportDecl to represent the invisible `import Prelude` that appears in any file that omits `import Prelude`, setting this field to indicate that the import doesn't appear in the original source. True => implicit import (of Prelude)

Offset of the block in the object file

Symbols exported by a block